[ Changed 3rd February 1998 ]
Many computer security applications depend on the secure storage of secret key material. The processors storing these keys cannot be protected by walls and guards in applications such as digital purses or pay-TV encryption systems; often the key memory has to be given into the hands of the attacker. Smartcards and other tamper-resistant processors are frequently quoted as a solution for this problem, but there is little published material about how difficult it is for attackers to circumvent the physical protection of these low-cost devices. The talk will discuss various techniques that have been applied to break the security processors used in pay-TV encryption systems and digital purses with much less effort then the manufacturers had hoped.